[3dem] partial gird de-vitrification in ultra-thin tip holders

[akshita wason]

Please remove me from your mailing list. Thank you.

On Fri, 11 Dec 2020 at 6:43 PM, Garry P Morgan <Garry.Morgan at colorado.edu>
wrote:

> Hello all,
> This is a question for those of you who have/use a Gatan Elsa holder, or
> any side entry cryo-holder with an ultra thin tip.  We have a high-tilt
> (thin tip) Elsa holder, and lately I’ve been seeing crystalline ice
> throughout the thinner areas of my cryo-grids, to the extent that I can see
> a diffracted electron beam on the grid bars in my low mag maps. In areas
> where the ice is on the thick side, the sample looks well vitrified. This
> consistently occurs when using the Elsa holder, bu t not with our older 626
> holders  (so I confident that I’m not mishandling my grids and doing
> something to warm them up after plunge freezing). I monitor the holder
> temperature throughout the transfer process, and this result can be seen
> even when the holder temperature readout remains close to -180C the entire
> time (ie, from transfer station, to airlock, to column). Has anyone else
> seen this? I’m wondering if the ultra thin tip could be allowing enough
> heat to partially devitrify my grid, but not enough to register a temp rise
> on the holder temp sensor.
> I’m open to any thoughts on how this might occur, and what could be done
> to prevent it.  i can send an image of my map if my explanation isn’t
> sufficient.
> thanks,
> Garry
>
> ________________________________
> Garry Morgan
> Director  —  Boulder EM Services —  Department of MCD Biology
> Campus Box 347  —  University of Colorado  —  Boulder, CO 80309
> phone:  303-492-8402
>
> _______________________________________________
> 3dem mailing list
> 3dem at ncmir.ucsd.edu
> https://mail.ncmir.ucsd.edu/mailman/listinfo/3dem
>
-- 

Kind regards,

Akshita
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.ncmir.ucsd.edu/pipermail/3dem/attachments/20201211/e85c06c8/attachment.html>